Rule Engine DSL Reference

RuleDock's Domain-Specific Language (DSL) allows you to create powerful sorting rules using readable expressions. This reference covers all available operators and patterns.

Overview

A DSL expression evaluates properties of a desktop icon and returns true or false. If true, the icon is sorted into the target fence.

Basic Example 
ext == '.png'

This matches any file with a .png extension.

Available Properties

You can reference these properties of each desktop icon:

Property Description Example Value
ext File extension (including dot) .png, .docx, .exe
name File name (without path) Screenshot_2026.png
path Full file path C:\Users\John\Desktop\file.txt

Comparison Operators

Equality (==)

Checks if a property exactly equals a value. Case-insensitive.

ext == '.PDF'     # Matches .pdf, .PDF, .Pdf, etc.
name == 'readme.txt'

Inequality (!=)

Checks if a property does NOT equal a value.

ext != '.tmp'     # Exclude temporary files
path != 'C:\Windows'

Contains (contains)

Checks if a property contains a substring. Case-insensitive.

name contains 'backup'   # Matches "backup.zip", "my_backup_2026.rar"
path contains 'Projects'

In List (in [...])

Checks if a property matches any value in a list.

ext in ['.jpg', '.png', '.gif', '.webp']   # Image files
ext in ['.doc', '.docx', '.pdf']          # Documents

Logical Operators

AND (and)

Both conditions must be true.

ext == '.png' and path contains 'Screenshots'

# Match: C:\Users\Screenshots\image.png
# No match: C:\Users\Documents\image.png

OR (or)

Either condition must be true.

ext == '.exe' or ext == '.msi'

# Match: setup.exe, install.msi

Combining AND and OR

AND has higher precedence than OR. Use complex expressions carefully:

# This means: (A AND B) OR C
ext == '.png' and name contains 'screenshot' or ext == '.gif'

String Quoting

Values can be quoted with single or double quotes:

name contains "my file"    # Double quotes
name contains 'my file'    # Single quotes
ext == .txt               # No quotes (simple values)

Use quotes when values contain spaces or special characters.

Regex Rule Type

For pattern matching beyond DSL, use the Regex rule type (not an expression operator). This applies a regex pattern to the file name.

Regex Examples 
# Match "Screenshot_20260205_123456.png"
^Screenshot_\d{8}_\d{6}\.png$

# Match version patterns like "app_v2.1.exe"
_v\d+\.\d+\.exe$

# Match files starting with "backup" or "archive"
^(backup|archive)

# Match any numbered file
\(\d+\)\.[a-z]+$   # e.g., "file (1).txt"

Regex Safety

All regex patterns are evaluated with:

  • Case-insensitive matching by default
  • 200ms timeout to prevent catastrophic backtracking (ReDoS)
  • Patterns that timeout are skipped silently

Complete Examples

Sort Design Files

Target: "Design" fence 
ext in ['.psd', '.ai', '.xd', '.fig', '.sketch']

Sort Development Files

Target: "Code" fence 
ext in ['.js', '.ts', '.py', '.cs', '.java', '.cpp', '.h']

Sort Project Screenshots

Target: "Project Screenshots" fence 
ext in ['.png', '.jpg'] and path contains 'Projects'

Sort Work Documents (Exclude Personal)

Target: "Work Docs" fence 
ext in ['.docx', '.xlsx', '.pptx'] and path contains 'Work' and name != 'personal'

Installers and Setup Files

Target: "Installers" fence 
ext in ['.exe', '.msi'] and name contains 'setup'
or
ext in ['.exe', '.msi'] and name contains 'install'

Troubleshooting

Expression Not Matching

  • Check for typos in property names (ext, name, path)
  • Remember comparisons are case-insensitive
  • Use the Preview feature in rule settings to test
  • Verify the file actually has the extension you expect

Regex Not Working

  • Test your regex on regex101.com first
  • Escape special characters: \. for literal dot, \\ for backslash
  • Complex patterns may timeout—simplify if needed